The purchase will expand Greystar's operations to 140,000 units in 88 markets in 25 states and Ontario, Canada.

JPI Management had managed 41,000 units. It has 1,150 workers who will remain with Greystar, bringing Greystar's employment to more than 4,000.

The National Multi Housing Council, an industry trade group, says Greystar was the nation's sixth-largest apartment manager with about 94,000 units as of Jan. 1, 2008. The fifth-largest manager had 133,000 units at the time.